Did Trump's Indictments Rally His Base? Evidence from the Counterfactual Format.

This article examines how former President Donald Trump's 2023 federal indictment for allegedly mishandling classified documents affected public opinion, comparing two retrospective self-assessment methods: the commonly used "change format" and the alternative "counterfactual format." The change format asks respondents directly how the event changed their attitudes, often producing biased results due to "response substitution," where partisans report attitude levels rather than actual changes. In contrast, the counterfactual format asks respondents to estimate their attitudes both with and without knowledge of the event, aiming to reduce this bias. Using a nationally weighted SurveyMonkey poll, the study finds that while the change format suggests the indictment increased Republican support for Trump, the counterfactual format indicates a small negative effect on Republican primary voters’ support and a modest increase in belief that Trump mishandled documents. The authors recommend the counterfactual format for assessing the causal effects of highly salient news events on public opinion, especially when most respondents have prior exposure and time-series data are unavailable or unreliable.